This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to test the concept of natural multiple HIV-1 Envelope quasispecies vaccines as a means of more effectively eliciting neutralizing antibodies (NAbs). This project will utilize envelope genes obtained from an HIV-infected subject who developed broad NAbs that meet the inclusion criteria for testing. These variants will be used as immunogens in DNA expression vectors in mixtures to "program" humoral immunity towards the development of broadly reactive Nab responses in vaccinated rabbits and macaques. We will compare repeated exposure to a single invariant sequence derived from early virus with repeated exposure to multiple variants[unreadable]the mixed approach[unreadable]or exposure to gradually changing, naturally derived variants[unreadable]the sequential "quasispecies" approach. We are using sequences from a subtype A infected subject from Kenya who developed broad NAbs in a few years post-infection. We have observed that the antibodies elicited by DNA vaccines in rabbits are able to neutralize specific variants that were part of the subject's quasispecies;development of neutralizing antibodies was dependent upon the use of codon-optimized sequences.